The feasibility of controlled repeatable (with a frequency of up to 2Hz) deflagration-to-detonation transition within a length of approximate to 3.5m and further detonation propagation at an average velocity above 1600-1700m/s in a 150-mm-diam tube, with an open end and separate supply of natural gas and air as fuel components, has been demonstrated experimentally. Based on experimental studies, a model of a pulsed-detonation combustor, and a prototype of industrial burners of a new generation, which produces a combined shock wave (mechanical) and thermal effect on objects blown on with combustion products, has been designed, constructed, and tested. Reported are the results of experiments demonstrating the pulsed-detonation combustor operation process in terms of cyclic detonation initiation via deflagration-to-detonation transition, as well as pulsed-detonation combustor thermal regime during long-duration (300s) testing without forced cooling. The results provide a basis for further work aimed at increasing the operation frequency and thermal power of pulsed-detonation combustors for different industrial (metallurgy, chemical engineering, waste incineration, etc.) and propulsion applications.